Surface mount electrical connector and an electrical terminal therefor

Abstract

An electrical connector (2) for mounting on a circuit board (4) comprises a housing (8) wiht through passages (10) each receiving an electrical terminal (38) having a transverse lance (76) with a free end (78) lodged in a recess (28) in a side wall (16) of the housing (2). Each terminal (38) has a solder tail (66) for engaging a pad (6) on the board (4), and from which projects a solder tail (66) having a soldering portion (68) outside the housing (2), for soldering to the pad (6) and being flexible about a reduced cross-section part (98). The foot (62) and the tail (66) have sheared edges (94 and 96). Sheared edge (96) engages the pad (6) to provide for high terminal density. The terminals (38) are moved inwardly of their passages (10) against the resilient action of their lances (76) when the connector (2) is applied to the board (4), to urge the sheared edge (96) against the pads (6) while the tails (66) are soldered to the pads (6).

We claim: 
     
       1. An electrical connector for mounting on a surface of a circuit board having pads thereon, the connector comprising: an insulating housing having terminal receiving passages extending therethrough and being provided with terminal retaining means; and   electrical terminals each received within a respective one of the terminal receiving passages and each having a mating portion and a pad engaging solder tail, said solder tail resiliently connected to said terminal and extending laterally beyond said housing, for engaging a pad, said solder tail having a pad engaging sheared edge, each of said terminals having a retaining member for cooperation with said terminal retaining means for affording limited movement of said terminal along its passage and for urging and maintaining said edge of the pad engaging solder tail into engagement with a respective pad on said circuit board when said electrical connector is mounted thereon.   
     
     
       2. A connector as claimed in claim 1, wherein the solder tail is connected to said terminal by way of a of reduced cross section neck and has an enlarged soldering portion positioned beyond said housing and being coplanar with the remainder of the soldering tail. 
     
     
       3. A connector as recited in claim 1, wherein said terminal further comprises a foot having a sheared edge extending from said terminal, proximate said solder tail, said foot extending along the longitudinal axis of said terminals a shorter distance than said solder tail, said foot for permitting limited rotation of said solder tail toward said terminal, said sheared edge for engaging the circuit board upon occurrence of said limited rotation for preventing excessive movement of said terminal. 
     
     
       4. A connector as recited in claim 3, wherein the sheared edges of each foot and the solder tail extending therefrom, are separated by a notch thereby defining said foot for preventing rotary movement of said terminal in its passage upon the terminal being subjected to a mating force, and defining a reduced cross section neck of the solder tail about which it can flex relative to said foot. 
     
     
       5. A connector as claimed in claim 3, wherein said foot and said solder tail are coplanar, the sheared edges of the foot and the solder tail being separated by a notch widening towards said sheared edges and providing a reduced cross section neck of said solder tail about which it can flex both in its own plane and transversely thereof with respect to the remainder of the terminal. 
     
     
       6. A connector as claimed in claim 1, wherein each terminal comprises an intermediate portion between said mating portion and said solder tail, each passage having a longitudinal wall formed with a recess, said retaining member being in the form of a resilient lance projecting from said intermediate portion obliquely across said passage and engaging in said recess. 
     
     
       7. A connector as claimed in claim 6, wherein said intermediate portion has a stop member projecting therefrom for engaging said lance to limit movement of said terminal outwardly of its passage. 
     
     
       8. A connector claimed in claim 6, wherein said intermediate portion comprises a stop engageable with a wall of said housing positively to limit movement of said terminal inwardly of its passage. 
     
     
       9. A stamped and formed, one-piece electrical terminal for engaging a pad on a circuit board, said terminal comprising: a mating portion for mating with a mating electrical contact element;   an elongate intermediate portion connected at one end to said mating portion and having a resilient lance projecting obliquely there across and having a free end projecting beyond one side of said intermediate portion;   a planar foot connected to the other end of said intermediate portion and having a sheared edge directed away from said intermediate portion; and   a resilient solder tail projecting from said foot transversely of said intermediate portion to a position beyond the free end of said lance and having beyond said free end, a soldering portion having a sheared edge and faces, for soldering to said pad.   
     
     
       10. A terminal as claimed in claim 9, wherein the solder tail is connected to said foot by way of reduced cross section neck, said foot and said tail being coplanar and said sheared edges being separated from each other by a notch defining said neck and a heel of said foot and having edges which converge towards said intermediate portion. 
     
     
       11. A terminal as claimed in claim 9, wherein said solder tail is uniplanar terminates in said soldering portion which is enlarged in the plane of the solder tail. 
     
     
       12. A terminal as claimed in claim 9, wherein said intermediate portion is formed with a pair of rigid tabs projecting from opposite edges of said intermediate portion proximate to said foot. 
     
     
       13. A terminal as claimed in claim 9, wherein said intermediate portion comprises a rectilinear, channel shaped part having a pair of opposed side walls connected by a web, said mating portion extending from one end of said channel shaped part and a stem at the other end thereof connecting said web to the said foot, said lance extending from one of said side walls beyond the other side wall, at said other end of the channel shaped part, a rigid stop member on said other side wall extending therefrom towards said lance and having a free end stop surface for abutment thereby. 
     
     
       14. A terminal as claimed in claim 13, wherein said stem is in the form of an elongate plate formed with a bight remote from said web and offsetting said foot from said web, a pair of rigid tabs projecting from opposite edges of said plate between said bight and said foot. 
     
     
       15. An electrical connector for mounting on a surface of a circuit board having pads thereon, the connector comprising: an insulative housing having terminal receiving passages extending therethrough and being provided with terminal retaining means; and   electrical terminals each received within a respective one of the terminal receiving passages and each having a mating portion and a pad engaging solder tail, said solder tail resiliently connected to said terminal and extending laterally of said passageway and beyond said housing, for engaging a pad, said solder tail having a pad engaging sheared edge, each of said terminals having a retaining member for cooperation with said terminal retaining means for affording limited movement of said terminal along its passageway and for urging and maintaining said edge of the pad engaging solder tail into engagement with a respective pad on said circuit board when said electrical connector is mounted thereon, each of said terminals further comprising a foot having a sheared edge extending from said terminal, proximate said solder tail, said foot extending along the longitudinal axis of said terminals a shorter distance when said solder tail, said foot for permitting limited rotation of said solder tail toward said terminal and said sheared edge for engaging the circuit board upon occurrence of said limited rotation for preventing excessive movement of said terminal.   
     
     
       16. A connector as recited in claim 15, wherein the sheared edges of each foot and the solder tail extending therefrom, are separated by a notch thereby defining said foot for preventing rotary movement of said terminal in its passage upon the terminal being subjected to a mating force, and defining a reduced cross section neck of the solder tail about which it can flex relative to said foot. 
     
     
       17. A connector as recited in claim 15, wherein said foot and said solder tail are coplanar, the sheared edges of the foot and the solder tail being separated by a notch widening towards said sheared edges and providing a reduced cross section neck of said solder tail about which it can flex both in its own plane and transversely thereof with respect to the remainder of the terminal. 
     
     
       18. An electrical connector for mounting on a surface of a circuit board having pads thereon, the connector comprising: an insulative housing having terminal receiving passages extending therethrough and being provided with terminal retaining means; and   electrical terminals each received within a respective one of the terminal receiving passages and each having a mating portion and a pad engaging solder tail, said solder tail resiliently connected to said terminal and extending laterally of said passageway and beyond said housing, for engaging a pad, said solder tail having a pad engaging sheared edge, each of said terminals having a retaining member for cooperation with said terminal retaining means for affording limited movement of said terminal along its passageway and for urging and maintaining said edge of the pad engaging solder tail into engagement with a a respective pad on said circuit board when said electrical connector is mounted thereon, said solder tail being connected to said terminal by way of a reduced cross section neck and having an enlarged soldering portion positioned beyond said housing and being coplanar with the remainder of the solder tail.   
     
     
       19. An electrical connector for mounting on a surface of a circuit board having pads thereon, the connector comprising: an insulative housing having terminal receiving passages extending therethrough and being provided with terminal retaining means; and   electrical terminals each received within a respective one of the terminal receiving passages and each having a mating portion, an intermediate portion and a pad engaging solder tail, said solder tail resiliently connected to said terminal and extending laterally of said passageway and beyond said housing, for engaging a pad, said solder tail having a pad engaging sheared edge, each of said terminals having a retaining member for cooperation with said terminal retaining means for affording limited movement of said terminal along its passageway and for urging and maintaining said edge of the pad engaging solder tail into engagement with a respective pad on said circuit board when said electrical connector is mounted thereon, said intermediate portion between said mating portion and said solder tail, each passageway having a longitudinal wall formed with a recess, said retaining member being in the form of a resilient lance projecting from said intermediate portion obliquely across said passageway and engaging in said recess.   
     
     
       20. A connector as recited in claim 19, wherein said intermediate portion has a stop member projecting therefrom for engaging said lance to limit movement of said terminal outwardly of its passage. 
     
     
       21. A connector as recited in claim 19, wherein said intermediate portion comprises a stop engageable with a wall of said housing positively to limit movement of said terminal inwardly of its passage.